of > by
7 And people's hearts with awful terror tie,
tie > [to] bind, [to] confine
8 A monstrous beast, bred in filthy fen, 9 He chose, which he had kept long time in darksome den.
107.17
Such one it was, as that renowmed Snake
2 Which great Alcides in Stremona slew,
Long fostred in the filth of Lerna lake,
4 Whose many heads out budding euer new,
Did breed him endlesse labour to subdew:
6 But this same Monster much more vgly was;
For seuen great heads out of his body grew,
8 An yron brest, and backe of scaly bras,
And all embrewd in bloud, his eyes did shine as glas.
1 Such one it was, as that renowned snake
snake > (The Hydra, which grew two heads for each one cut off: it lived in the swamps of Lerna Lake in Argos and was killed by Hercules as his second labour; see Met. 9.68-74)
2 Which great Alcides in Stremona slew,
Alcides > (Another name for Hercules, grandson of Alceus)
Stremona > (Perhaps another name for Thrace, of which the River
Strymon forms one boundary. Thrace was noted for its seditions
(Upton); though Lerna was not in Thrace)